This invention relates to superhard products such as diamond, polycrystalline diamond, and cubic boron nitride produced by the high pressure and high temperature (HPHT) method. More particularly this invention relates to the HPHT containers or can assemblies in which the superhard materials are processed. Superhard materials by the HPHT method are produced by encapsulating the materials into a container, variously known in the art as a container, a can, an enclosure, a cup, a shield, and a tube.
U.S. Pat. No. 4,333,902 which is herein incorporated by reference for all that it contains, discloses a process of producing a sintered compact comprises filling a cup with a powdered material to be sintered, putting on an opening of the cup a covering member consisting of a lid and solder so as to permit ventilation between the interior and exterior of the cup to form a cup assembly, applying heat as well as vacuum to the cup assembly to degas the powdered material, melting the solder by the continuation of heat to air-tightly seal the cup with the lid to obtain a closed cup compressible under high pressure at high temperature while maintaining the air-tight seal, and hot-pressing the closed cup to obtain a sintered compact. The covering member may include a porous lid closing the cup and a solder put on the porous lid.
U.S. Pat. No. 4,425,315 which is herein incorporated by reference for all that it contains, discloses a diamond sintered compact wherein diamond crystal particles are uniformly orientated in a particular direction and the method for producing the same, and has for an object to provide a diamond sintered compact having a high thermal conductivity particularly suitable for heat sink for use in the field of electronics. According to the invention, graphite is used as carbonaceous raw material, diamond crystal particles having such elongated shape that the ratio of the length of the long axis to that of the short axis is more than 2 being synthesized in such state that the greater part of the crystal particles have their long axes uniformly oriented in a particular direction, the crystal particles being sintered in the direction of the long axes thereof so that transformation of the graphite into diamond and sintering thereof may be accomplished synchronously. The invention has for an object to obtain a diamond sintered compact suitable for the aforesaid use by degassing reaction system raw material plugged into an air permeable container by heating it in vacuum in order to intercept gaseous components causing a decrease of thermal conductivity at the time of synthesizing diamond from carbonaceous material and a catalytic metal and sintering thereof, subsequently the air permeable part of the said container being sealed by means of soldering material preliminarily placed in contact with the said container.
U.S. Pat. No. 4,425,315 which is herein incorporated by reference for all that it contains, discloses a diamond sintered compact suitable for the aforesaid use by degassing reaction system raw material plugged into an air permeable container by heating it in vacuum in order to intercept gaseous components causing a decrease of thermal conductivity at the time of synthesizing diamond from carbonaceous material and a catalytic metal and sintering thereof, subsequently the air permeable part of the said container being sealed by means of soldering material preliminarily placed in contact with the said container.
U.S. Pat. No. 6,596,225 to Pope et al. which is herein incorporated by reference for all that it contains, discloses sealing of the can by electron beam welding at high temperature and in a vacuum.
U.S. Patent Publication 2005/0044800 A1 which is herein incorporated by reference for all that it contains, discloses an assembly for High-Pressure High-Temperature (HPHT) processing comprising a can, a cap, a meltable sealant and sealant barrier, and a superhard mixture comprising superhard particles. The superhard particles may be positioned adjacent a substrate of cemented metal carbide. The can and cap contain the superhard mixture with the sealant barrier positioned within the assembly so as to be intermediate the sealant and at least a portion of the mixture, thereby preventing the sealant from coming in contact with the mixture during processing. The assembly is placed within a vacuum chamber and heated to a temperature sufficient to cleanse the assembly and then melt the sealant providing a hermetic seal for the assembly in preparation for further HPHT processing.